Remove assignment to variable that gets overriden and never used

Signed-off-by: Cleber Rosa <[email protected]>

Author: clebergnu

podman_compose.py

@@ -1668,7 +1668,7 @@ def _parse_args(self):
         parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
         self._init_global_parser(parser)
         subparsers = parser.add_subparsers(title="command", dest="command")
-        subparser = subparsers.add_parser("help", help="show help")
+        _ = subparsers.add_parser("help", help="show help")
         for cmd_name, cmd in self.commands.items():
             subparser = subparsers.add_parser(
                 cmd_name, help=cmd.desc